1. Field of the Invention
The present invention relates generally to a method and apparatus for pyrolysis of waste materials. More particularly, the invention relates to a novel method and apparatus for pyrolyzing waste materials and recovering useful chemical and energy producing materials therefrom.
2. Discussion of the Prior Art
The search for new energy sources has become increasingly important due to the rapid rate of depletion of existing fossil fuels. One of the more promising sources of new energy is waste materials presently being discarded or destroyed. By techniques of pyrolytic decomposition, many types of waste materials can be converted into energy rich fuels such as combustible gases and char, or fuel carbon.
In the past, several types of devices for pyrolyzing refuse and other waste products have been suggested. Many of these devices have proved unworkable or economically unfeasible. Others, while feasible in concept have been proven to be inefficient and unreliable in continuous operation. Still others, while attractive in theory, have been shown to be too expensive to manufacture, install and operate.
Among the most successful prior art refuse conversion devices are the devices described in U.S. Pat. Nos. 2,886,122; 2,993,843; 3,020,212; and 3,098,458. The present invention constitutes an improvement upon certain of the devices described in these patents.
As will become apparent from the description which follows, several important improvements to the apparatus described in the aforementioned patents have been made. One such improvement relates to the novel method and apparatus for continuously withdrawing a portion of the combustion gases generated by the pyrolysis of the waste, precisely mixing these gases with preheated oxygen or air and then using the highly combustible gaseous mixture thus formed to pyrolyze the waste products continuously being introduced into the apparatus. This technique also minimizes condensation problems and the undesirable buildup of materials within the gas recovery and recycling sub-systems.
Another important improvement of the apparatus of the present invention relates to a novel high temperature, liquid medium sealing means for effectively sealing the combustion chamber of the apparatus to prevent undesirable leakage of air into the chamber and at the same time prevent the escape of combustion gases therefrom.
Still another important feature of the invention concerns a unique waste material distribution means for uniformly distributing within the combustion chamber waste materials being introduced into the apparatus.
The apparatus of the present invention, embodying the aforementioned improvements, for the first time enables the highly efficient, self sustaining, continuous processing of combustible materials under air tight conditions to economically produce highly useful chemical by-product materials as well as energy rich materials such as combustible gases and fuel carbon.